Comparison between abundance ratios of [α/Fe], [Mg/Fe], [Si/Fe], [Ca/Fe], [Ti/Fe] as a function of [M/H] predicted by the three-infall model for stars younger than 1 Gyr compared and Gaia DR 3 massive stars. Black points indicate observed massive stars selected by Gaia Collaboration (2023b, see text for details) using the calibrations proposed by Recio-Blanco et al. (2023). The contour lines enclose fractions of 0.75, 0.60, 0.45, 0.30,0.20, and 0.05 of the total number of observed stars. The colour-coded hexagons indicate the model predictions and highlight the total number of stars formed by the fiducial three-infall model in the different regions of the abundance ratio relation.